“The facts of life took on a fiercer aspect, and while he faced that aspect without retreat, he faced    
   it with all the latent cunning of his nature aroused.” (2011: 11).
Gradually, Buck was accustomed to the severe life and toil in the north among the fierce competition and arduous living environment. He learnt a lot and became stronger day after day.
 
Not only did he learn by experience, but instincts long dead became alive again, that was his heredity. The domesticated characteristics fell from him. In vague ways he remembered back to the primeval forest. It was easy for him to learn to fight with cut and slash and the quick wolf snap. In this manner had fought forgotten ancestors. They quickened the old life within him, and the old tricks they had stamped into the heredity of the breed were his tricks. They came back to him without effort (London, 2006: 23).

It was this kind of heredity in his breed that brought the old and distant song of his ancestors’ back to him, and he came into his own again.

3.2 The Environment of the Icy North
The Alaskan Panhandle and the Yukon Territory form the backdrop for a noble dog’s decision to turn his back on civilization. Consequently, to fully understand Buck’s st ory and the naturalism reflected in it, it is imperative to know the basic environment and treaties Buck encountered and analysis their influences on the great changes in Buck.

3.2.1 The Cruelty of the Natural Environment
The primary areas related to Buck’s story are the Alaska Panhandle, now a part of the United States, and the Yukon Territory, now a part of Canada. These two areas were unknown to most of the world at the turn of the 20th century and even today are still remote and sparsely inhabited. The weather in both denies any easy inhabitation.

Some of the places they traveled even lies inside the Arctic Circle. Hard winter prevails for all but two month of the year, with temperatures that in some places falling to seventy degrees below zero. The masters of Buck and his group must know how imperative it was to warm and dry if they got wet, because they would freeze in an instant, and death was a certainty. Trees are hardly to survive, and mountains are covered by glaciers. Most of the areas are covered by permafrost, constantly frozen ground just beneath the surface layer. A terrible problem occurred from instability when rises in temperature thaw the permafrost temporarily. In The Call of the Wild, when the ice beneath the snow melted, the whole dog teams trapped into the icy water, and even several partners vanished into the terrible water, when the drivers were not aware of the huge fatal danger.
At night, the dogs had no place to sleep except burying themselves in the freezing snow. At first, Buck, as a fresh dog, couldn’t find a place to rest in the chilling wind but his peers disappeared; he even broke into the instant camps of his drivers, but was driven out immediately with mockery.
Finally, he found the secret and became accustomed to the rule environment. Meanwhile, Buck, just like his ancestors, was more alert in the wild:
  “The snow walls pressed him on every side, and a great surge of fear swept through him—the fear of the wild thing for the trap. It was a token that he was harking back through his own life to the life of his forbears.”(Wang, 2011: 19)
 
Buck and his fellows toiled day after day. They always broke camp in the dark, and found themselves leaving miles behind when they saw the first gray of dawn. However, what they can get to eat was a bit of fish; where they can have a rest was crawling into the snow. Buck never had enough and suffered from perpetual hunger pangs. He swiftly lost the fastidiousness which had characterized his old life in the south. In order to live in such a poor condition, Buck fastened the rhyme of eating and learned to steal meat when some turned his back: 自然主义在《野性的呼唤》中的体现(5):http://www.youerw.com/yingyu/lunwen_132.html